EP 0321315 A2 19890621 - Half tone printing or display apparatus.
Title (en)
Half tone printing or display apparatus.
Title (de)
Rasterdruck- oder Rasteranzeigegerät.
Title (fr)
Appareil d'impression ou de visualisation en demi-teintes.
Publication
Application
Priority
US 13503187 A 19871218
Abstract (en)
A method and apparatus for effecting enhanced digital half-tone reproduction using a binary displaying device promotes good colour tone fidelity while retaining high spatial resolution. The input image is subdivided into a matrix of component pixels each representing an intensity value at a corresponding image location. The intensity is related to the maximum possible intensity of the pixel and the decision to print is made on the basis of the intensity relation of the pixel and an internally generated pseudo-random number. In one embodiment a number of display deciding matrices are stored in memory and one matrix is selected in accordance with the intensity relation of the pixel and a location in the selected matrix is accessed in accordance with a pseudo-random number with the information at that location used to decide whether or not to display the pixel.
IPC 1-7
IPC 8 full level
B41J 2/52 (2006.01); B41J 2/485 (2006.01); H04N 1/405 (2006.01); H04N 1/52 (2006.01)
CPC (source: EP)
H04N 1/4058 (2013.01); H04N 1/52 (2013.01)
Designated contracting state (EPC)
BE DE FR GB IT NL
DOCDB simple family (publication)
EP 0321315 A2 19890621; EP 0321315 A3 19910102; JP H022042 A 19900108
DOCDB simple family (application)
EP 88312033 A 19881219; JP 31656388 A 19881216